Trading system

The Market Operator’s Information System (SIOM) is configured from an external standpoint with respect to the operating company, as the access tool used by market agents to participate and obtain information from the electricity market. Internally, SIOM is configured as the access tool used by the different departments of the same company to store, process and access information generated by the market.

SIOM system access is performed using secure web sites for the agents of the Electricity Market. Access to it's services is only granted to those that are authorized.

See documentation available on the website "Technical documentation" within this same section for the correct configuration of your agent work station. This documentation is also available on through link “Help and Documentation”.


From this standpoint, SIOM is designed to provide the following main functions:

  • Allow agents to present bids on the daily or intraday electricity markets.
  • Match the different markets
  • Exchange information with the System Operators in connection with the market and the different ancillary services.
  • Provide agents with the necessary information on market results.
  • Carry out market settlements, manage invoicing data, charges and payments made by the company and agents, and provide results to all market agents.
  • Automatically generate reports on the operation of the market.
  • Provide the operating company with value added information on the behaviour of the market.
  • Deal with claims presented by agents in connection with matching or settlement results.

All these functions shall always be performed by ensuring that SIOM fulfils the following basic requirements:

  • Functional reliability and robustness, providing for correct operation at all times.
  • Redundancy in equipment, comunications and software, giving high disponibility functionality to the system.
  • Flexibility in equipment, communications and software used, ensuring the proper functioning of the system in the event of simple failures in any of its components.
  • Application scalability , allowing the system to evolve as new agents enter the market.
  • System security, preventing access to the market by external elements and guaranteeing the confidentiality of agent information, pursuant to existing regulations.

SIOM commenced operation in the daily market area on January 1, 1998, and began processing the intraday market on April 1.

In November 2004, SIOM2 was put into operation, including new technologies such as J2EE, XML and Web Services as new mechanisms provided to the market participants to access the electricity market. The system SIOM2 maintains SIOM described functionality, adding the following enhancements:

  • Provides a new interface application-to-application, by using web services, complementing the actual SIOM navigator access and allowing market participant application integration with their electricity market operations.
  • Using XML as the new information exchange format, following the actual trends in technology international standards.
  • Includes the digital signature standard XML-Signature in the operational data sending and modification transactions, providing added functionalities for auditing and verification to those provided by SIOM.

The new Web Services access interface (B2B) is the more appropriate for those market participants willing to automate the connection to OMEL directly from their own corporate systems. The actual connection method using Internet navigator and requiring human intervention, as the one provided with SIOM, is still operational and complements the new Web Services.